allow now typing into a drop down combo box

I have a drop down combo box and the users do not want any of the items in the list to default so I need it to generate and error if anyone tries to type text into the field.

I did an on key press subroutine but it still allows one character to be saved if they do it a certain way. Any one got any ideas on how to fix this:

heres my code:

cboCategory.Text = ""
MsgBox "Please only select from the list of choices"
cboCategory.Text = ""
code still can allow an accidental saving of one character like "f" or whatever key last pressed
items in my list

Accounting
Misc
Service
Enforcement
Coll & Dist

these are bound to fields in an Access database

thank you

Why don't you just set the Combobox's Style Property to 1 - Dropdown List, then they would be forced to only select items from the dropdown list.